Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753844AbWKFVuI (ORCPT ); Mon, 6 Nov 2006 16:50:08 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753843AbWKFVuH (ORCPT ); Mon, 6 Nov 2006 16:50:07 -0500 Received: from mx1.redhat.com ([66.187.233.31]:21990 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S1753785AbWKFVuF (ORCPT ); Mon, 6 Nov 2006 16:50:05 -0500 Message-ID: <454FAE0A.3070409@redhat.com> Date: Mon, 06 Nov 2006 15:50:02 -0600 From: Eric Sandeen User-Agent: Thunderbird 1.5.0.7 (X11/20060913) MIME-Version: 1.0 To: Linux Kernel Mailing List , linux-fsdevel CC: Theodore Tso Subject: [RFC/PATCH] - revert generic_fillattr stat->blksize to PAGE_CACHE_SIZE Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3053 Lines: 79 The inode diet patches first did this to generic_fillattr(): - stat->blksize = inode->i_blksize; + stat->blksize = PAGE_CACHE_SIZE; but by 2.6.19-rc3 this was changed again: - stat->blksize = PAGE_CACHE_SIZE; + stat->blksize = (1 << inode->i_blkbits); I can't find for sure why this was done; perhaps because it exposed a bug in cifs[1] However, if we are going to pick a default for generic_fillattr, it should probably be what most filesystems were using before, and let filesystems which need something else re-set it to according to their needs. As it stands today, doing readdirs and the like in block-sized chunks rather than page sized will probably not be the best thing for performance. A bit of quick parsing of the original inode diet patch shows that by far most filesystems were using the page size: (count) (line which sets i_blksize) 1 cifs_inode->vfs_inode.i_blksize = CIFS_MAX_MSGSIZE; 1 i->i_blksize = 512; 1 inode->i_blksize = attr->va_blocksize; 1 inode->i_blksize = befs_sb->block_size; 1 inode->i_blksize = HFSPLUS_SB(inode->i_sb).alloc_blksz; 1 inode->i_blksize = HFSPLUS_SB(sb).alloc_blksz; 1 inode->i_blksize = HFS_SB(inode->i_sb)->alloc_blksz; 1 inode->i_blksize = HFS_SB(sb)->alloc_blksz; 1 inode->i_blksize = HPAGE_SIZE; 1 inode->i_blksize = NCP_BLOCK_SIZE; 1 inode->i_blksize = QNX4_DIR_ENTRY_SIZE; 1 inode->i_blksize = (u32)osb->s_clustersize; 1 inode->i_blksize = xfs_preferred_iosize(mp); 1 ino->i_blksize = i_blksize; 1 ino->i_blksize = proc_ino->i_blksize; 1 ip->i_blksize = ip->i_sb->s_blocksize; 1 ip->i_blksize = PAGE_SIZE; 2 inode->i_blksize = fattr->du.nfs2.blocksize; 2 inode->i_blksize = inode->i_sb->s_blocksize; 2 inode->i_blksize = reiserfs_default_io_size; 2 inode->i_blksize = sbi->cluster_size; 2 vi->i_blksize = PAGE_CACHE_SIZE; 3 inode->i_blksize = sb->s_blocksize; 3 ret->i_blksize = PAGE_CACHE_SIZE; 5 inode->i_blksize = 1024; 7 inode->i_blksize = 0; 12 inode->i_blksize = PAGE_SIZE; 22 inode->i_blksize = PAGE_CACHE_SIZE; so I would propose the following patch to make PAGE_CACHE_SIZE the default (again), and let filesystems which need something -else- do that on their own. [1] http://lists.samba.org/archive/linux-cifs-client/2006-September/001481.html Thanks, -Eric Signed-off-by: Eric Sandeen --- linux.orig/fs/stat.c 2006-11-05 23:27:04.962482569 -0600 +++ linux/fs/stat.c 2006-11-05 23:27:29.394396050 -0600 @@ -33,7 +33,7 @@ stat->ctime = inode->i_ctime; stat->size = i_size_read(inode); stat->blocks = inode->i_blocks; - stat->blksize = (1 << inode->i_blkbits); + stat->blksize = PAGE_CACHE_SIZE; } EXPORT_SYMBOL(generic_fillattr); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/